sparse bundle error

[sjk]

The permissions at that level looks fine.

I doubt it matters for this, but if you run File > Get Info (Command-I) on the /Volume/Backup volume in Finder is "Enable ownership on the volume" under the bottom Sharing & Permissions section checked or unchecked?

Next I'd run find /Volumes/Backup -name '*.sparsebundle' in a Terminal shell to find the .sparsebundle pathname(s), e.g.:

% find /Volumes/Backup -name '*.sparsebundle'
/Volumes/Backup/eMac/Macintosh HD@lovelight.sparsebundle
/Volumes/Backup/iMac/Media@halo.sparsebundle
/Volumes/Backup/iMac/Users@halo.sparsebundle

After you've found one that's causing SD! trouble you can run ls -dl /Volume/Backup/path/to/file.sparsebundle to view its permissions. And if you open the folder it's in then try opening the actual .sparsebundle (by double-clicking it) you'll get an error if it's a permissions problem (like I suspect).

Sorry I don't have an instant answer/solution. The info I'm asking for helps analyze and understand the cause of the problem before moving further.